Not me. BUT, I do have a low wattage pet heating pad that is USB powered and can run on a power bank, if needed.@micstrachan and/or I think, @ChicoryBlue use a heating pad. Wrap it around the roost, then wrap and old towel around that (to protect the pad & moderate the direct heat some), fasten the towel (ball bungies work great) on and viola', toasty warm roosts. ?@BY Bob might have tried this, too.
I haven't done this as I have no electricity at my coop, but whichever one posted that idea previously seemed to like it/stated it worked well for them.
